Methyl cellulose as starch substitute



United States Patent 3,402,056 METHYL CELLULOSE AS STARCH SUBSTITUTEJohn W. Ehrmantraus, Midland, Mich, assignor to The Dow ChemicalCompany, Midland, Mich, a corporation of Delaware No Drawing.Continuation-impart of application Ser. No. 502,415, Oct. 22, 1965. Thisapplication Oct. 18, 1967, Ser. No. 676,026

4 Claims. (Cl. 106-170) ABSTRACT OF THE DISCLOSURE As a substitute forstarch to be employed as a gas propelled spray from a pressurized can, awater dispersion of a methyl ether of cellulose of standard viscosityfrom 5 to 25 centipoises and, thermal gelation temperature in water notabove 100 0, together with a foam breaking agent and, optionally, otheradditives.

Relationship to other applications This application is acontinuation-impart of my copending application Ser. No. 502,415, filedOct. 22, 1965, and now abandoned.

Background of the invention It is well known to prepare a thin waterdispersion of a hydrated, cooked, gelatinized starch, such as cornstarch, at from about 1 to about 5 weight percent concentration ofstarch by weight of total aqueous preparation, and to package theresulting aqueous dispersion in a gas-propelled spray can whereby tospray the dispersion of starch onto a fabric, such as a mans shirt,prior to ironing it. Starch used thus becomes yellow in a relativelyshort time, and unless the resulting starch-treated article is usedpromptly, and thereafter laundered, assumes an irregular and unsightlyyellow color from the starch.

Furthermore, moist starch has a tendency to build up, that is to say, toform a difiicultly removable deposit on the sole plate of the iron withwhich -a starched article is later ironed smooth as water is dried fromthe starch preparation during ironing.

Further, starch emulsions are excellent media for the growth of manymicroorganisms, and it is necessary to use a cooked starch promptly, orelse to incorporate some anti-microbial substance in such starchpreparation to prevent its deterioration. Further, articles which havebeen treated with starch and ironed tend to be stiff in the sense thatif a dry, smooth, ironed surface of such fabric be sharply inflected, ittends to break along a line, and there results an undesirable crease orwrinkle which can be removed usually only by re-starching andre-ironing. Moreover, if an undesired crease or wrinkle is accidentallyironed into a starched fabric, its removal is often nearly impossibleunless the process is begun all over again with a thorough wetting ofthe fabric.

In the attempts to avoid some of the disadvantages of of starch, thecarboxyalkyl celluloses, represented by carboxymethylcellulose,typically in the form of its sodium salt, have been employed as asubstitute for starch. While this product offers various advantages overstarch, it has the disadvantage that it undergoes at least incipientpyrolysis and discoloration at temperatures substantially lower thanthose employed in ironing most fabrics which are starched. In theattempt to deal with this problem, some commercially packaged suchproducts carry on the label a legend advising the user to set thetemperature of the iron at one fabric position lower than that at whichit would ordinarily be set. Thus, for ironing linen one sets it atcotton; for ironing cotton, one sets it at wool and so forth. Thisapproach is undesirable in that even 3,402,056 Patented Sept. 17, 1968when such instructions are followed, scorching can occur easily;moreover, the practice denies the use, on the treated fabric, of theheat necessary to effect a satisfactory ironing of the fabric.

Prior art Historically, US. Patents 1,926,396, 2,021,981 and 2,321,023are of interest, telling of the development of fluorocarbon propellants,their use under autogenous pressure, and such use when employed assolvents for active materials.

Patent 3,068,120 teaches a pressure can spray of a water solution of thesodium salt of carboxymethylcellulose.

Description of the present invention According to the present invention,disadvantages of the prior art are overcome and certain advantages arepresented, through the use, as a starch substitute, of certain methylethers of cellulose, which can have certain substituents other thanmethyl etherifying groups on the anhydroglucose units of the cellulosepolymer structure.

The methyl ethers of cellulose, optionally with other substituents, arewell known, being marketed under the trademark Methocel.

Several properties of a methyl ether of cellulose can be controlledwithin close tolerances in manufacture, and typically two suchproperties are specified with respect to each such commercial product.One is the lower limit thermal gelation temperature, and the other isthe viscosity in centipoises at room temperature, both beingascertained, for standard reference purposes, as properties of a twoweight percent water solution. Identity of substituents is also readilycontrolled.

The methyl cellulose ethers to be employed according to the presentinvention are those of which the standard 2 percent aqueous dispersionhas an Ubbelohde viscosity in the range of from 5 to 25 centipoises. Theconcentration to be employed will be adjusted according to the inherentviscosity of the methyl ether of cellulose employed, but typicallyconcentrations in the range of from about 0.1 to about 5 percent ofmethyl ether of cellulose by weight of total aqueous preparation aresatisfactory. When concentrations lower than this are employed,irrespective of the innate viscosity of the ether, the resulting drydeposit after ironing tends to be so light as not to contributesatisfactorily to the body or stiffness of the fabric. When aconcentration greater than about 5 percent is employed, irrespective ofthe viscosity of the starting ether, the viscosity of the resultingaqueous dispersion tends to be too great for elficient distribution onand in a fabric, or from a gas-propelled spray can.

It is essential and and critical to the present invention that theemployed cellulose ether have, in addition to some methyl etherifyinggroups, as at least a significant part of its etherifying groups, alower alkyl group, preferably further methyl, or ethyl, propyl,isopropyl, butyl, isobutyl or tertiary butyl. It may in addition have,and in some cases desirably will have, as part of its etherifyinggroups, hydroxy lower alkyl groups, such as hydroxyethyl, 2 or 3-hydroxypropyl, or 2-, 3-, or 4-hydroxybutyl groups, or their simpleisomers.

While the properties of any chemical substance are the properties of thewhole substance, it now appears to the present inventor, in the use ofcellulose ethers as spray starch substitute material, that the presenceof lower alkyl etherifying groups which are non-ionic in some way actsto render the resulting product less susceptible to scorching than aresimilar substances with other substituents, notably ionic substituentssuch as carboxyl and salts of carboxyl. However, when a significantproportion of loweralkyl etherifying groups are present and the exactproportion can varythen some proportion of other etherifying groups ispermissible. For example, by the presence of hydroxypropyl orhydroxybutyl etheri fying groups, the water dispersibility of theresulting substance may be improved over the properties of an other wisesimilar substance lacking such groups. Also, the thermal gelationtemperatures of cellulose ethers thus substituted are elevated over thecorresponding temperatures of substances without such substituents, andthis can be advantageous in some spray starch preparations.

All these products contemplated to be used in the present invention areto at least a predominant extent methyl ethers of cellulose and are thusgenerically referred to, but not chemically strictly limited as, methylethers of cellulose.

The methyl ethers of cellulose as here defined possess the heredesirable property of thermal gelation. Thus, when .a fresh aqueousdispersion is applied to a fabric and the fabric is then ironed, uponbeing heated by the hot iron, the aqueous dispersion of methyl ether ofcellulose tends to gel with the result that the fabric behaves nicelyunder the iron and the smoothing of wrinkles is easily achieved.However, as the treated fabric is further ironed, water tends to beevaporated. When, subsequently, the fabric cools, the gelation thatresulted from heating tends to disappear. The resulting dry fabric has adesirable hand and stiffness, but it has little or none of thebrittleness characteristic of a starched fabric. As to the thermalgelation temperature of the aqueous methyl ether of cellulose, aproperty controllable in manufacture, it is not critical what thistemperature be so long as it be lower than the boiling temperature ofwater under atmospheric pressures. The presence of water in the methylether dispersion tends to limit temperature rise in the fabric throughthe moist phase and until the fabric is essentially dry, and it isduring this moist phase that the thermal gelation of the methylcellulose is most desirable. Thus, methyl cellulose ethers of which thethermal gelation temperature is as low as 50 C., or as high as 90 or 95C., can be employed. Those with lower thermal gelation temperatures willbe preferred for fabrics that are usually ironed at lower temperatures.

While the methyl ether of cellulose can be used to treat a fabric as asimple aqueous dispersion, such dispersion is, without more, not adaptedto be employed in a spray container. If there is employed a pressurizingagent which is not emulsifiable in the aqueous preparation, the aqueouspreparation tends to issue as a small, hard stream not at all adapted tobe evenly distributed over an area of fabric. If there is employed apropellant which emulsifies in the aqueous methyl cellulose preparation,without more, the product tends to issue in the form of a lather orfoam. Such lather is also difficult to use successfully. To prepare apractical methyl cellulose aerosol spray mixture, it is necessary to usean emulsifiable propellant in some way so that the resulting emulsionbreaks almost instantaneously as the gas-propelled mixture issues fromthe orifice of the spray container. Moreover, any substance added to thetotal mixture must be colorless, must be no more susceptible ofdiscoloration with ageing than is the methyl cellulose, nor may itinduce scorching or other undesirable performance more readily.

There is value for some users of a starch or like product, in productionby the employed material of a certain amount of drag upon the sole plateof the iron. Some users find that this drag subtly changes with changingwater content, abundance of employed material, and the like, and servesto indicate various matters to the user, such as the progress of theironing. For others it enables a more ready smoothing and flattening ofthe fabric, and for yet others the value appears to be purely esthetic.When it is desired to have a maximum of such drag, a simple aqueousdispersion of a methyl cellulose within the limits before defined can beprepared, combined with an emulsion breaking substance, and

4 packaged in a container with an emulsifiablc propellant. When it is.desired to reduce the drag" of the iron, a lubricant can be added.Known lubricants are satisfactory, such as an emulsion of apolydimcthylsiloxane cil, or a light, emulsifiable parafiin oil.

When it is desired to employ a substance such as isobutane or a Freon aspropellant by reason of its desirable pressure properties,emulsifiability of the propellant in the aqueous methyl celluloseproduct can be enhanced by the addition to the aqueous preparation of amodest amount of a glycol ether. One such substance which has givenexcellent results is the butyl ether of ethylene glycol. Also useful isthe ethyl ether of ethylene glycol, or the normal butyl or ethyl etherof diethylcne glycol, or a commercially available mixture of glycolethers which is a mixed isobutyl ether of mixed lower alkanediols,typically propylene glycol and its homologs. These substances tend alsoto facilitate the even application of the product to fabric bypossessing wetting properties different from those of water or waterwith conventional Wetting agents. It is essential and critical in thepresent invention to avoid, and for all practicable purposes to exclude,substantially dissociated ionic substances from the resultingpreparation. The presence of such ionic substances appreciably enhancesthe thermal discoloration or scorching of fabrics at ironingtemperatures.

Description of embodiments preferred and excluded Example 1: Acommercial methyl cellulose of which a 2 percent aqueous solution at 20C. has an Ubbelohdc viscosity of 10 eentipoises was employed. 35 gramsof this methyl ether of cellulose were mixed with 500 grams of water atbetween and C. It is well known that the methyl ethers of cellulose aredispersed readily in hot, but not readily in cold, water. When thedispersion was completed, the resulting hot dispersion was diluted andcooled by the addition thereto of 1395 grams of a mixture of water andcracked ice. There was thus 00- tained a clear aqueous dispersion ofmethyl cellulose containing slightly more than 0.5 weight percent of thecellulose ether by weight of total aqueous dispersion. To the resultingmethyl cellulose dispersion were added 60 grams of 2-butoxyethanol, 4grams of a commercial foam breaking colloid consisting essentially of apolyvalcnt metallic soap, a non-ionic emulsifier, and a hydrocarboncarrier; and 6 grams of a commercial emulsion of a polydimethylsiloxaneoil of a molecular weight on the order of 5x10 The resulting dispersionwas somewhat less limpid but was yet essentially transparent. Of theresulting preparation there were 2005 grams, and this was dividedapproximately equally into 5 aerosol cans each of a nominal capacity of16 ounces. The cans were sealed and charged with 45 grams of isobutanepropellant, obtaining a resulting pressure on the order of 40 pounds persquare inch gauge at room temperatures: and were then provided withactuators.

Example 2: A mans shirt of white cotton tabrie, having been recentlylaundered and tumble-dried in an artificially heated dryer and generallyirregularly wrinkled from this laundering and drying, was spread on anironing board and upon a surface thus spread and smoothed approximatelyfiat was sprayed an amount of contents of a pressure can preparedaccording to Example 1 suiticient that the sprayed area appearedgenerally moist with individual droplets of moist aqueous starchsubstitute deposit visible here and there. The moistened smoothedsurface was then ironed in conventional manner, using athermostat-controlled electric iron of which the sole plate was heatedto a temperature of approximately 230 C. The ironing process wasunhurried, and the ironed surfaces became acceptably smoothly flat andof the appearance desired in a well-ironed cotton fabric. No evidence ofscorching was seen. Upon completion of the ironing, no visible evidenceof the deposit of starch substitute was noticeable; however, whengrasped, the fabric manifested a desirable hand, that is to say, elasticresilience to crushing and the like.

In similar manner, all areas of the shirt were sprayed, at theconvenience of the individual doing the ironing, and thereafter ironedto obtain a white shirt of conventional clean, well-ironed appearance.

As a result of this process, there accumulated on the sole plate of theiron a small amount of a white deposit. It did not char, and if any ofthe deposit exchanged with substances in or on the shirt, the resultswere invisible.

The iron was permitted to cool to approximately room temperature, andthereafter wiped with a moist paper towel, and it was observed that thedeposit was removed quickly and easily and with very little effort.

Example 3: Three mens white shirts are prepared in the manner describedin Example 2. One of them is conventionally folded, by buttoning the topbutton, turning the shirt face down, folding the sleeves so that thecuffs come up to the yoke, infolding the sides to narrow the dimensionsof the shirt, and folding the tail twice over toward the yoke, to obtainan essentially rectangular shirt folded over a cardboard stiffener inthe manner conventionally employed in the sale of new shirts and in thepresentation of professionally laundered shirts. Essentiallysimultaneously, another shirt essentially identical except that insteadof the starch substitute of the present invention, there is employedcorn starch in its finishing, is similarly folded. Both shirts, firstoverwrapped with plastic sheeting, are placed side by side in a dresserdrawer and both are loaded by placing on top of each 5 essentiallyidentical shirts. They are permitted to remain in this condition for aday, and thereafter removed, the overwrap of plastic removed, and theshirts unfolded. The shirt described as being finished With starch showswell defined creases along the line of each fold; the shirt described asbeing prepared with the composition of the present invention shows suchcreases initially but upon a few moments hanging on a clothes hangerloses such creases and presents essentially a smooth, well-ironedfinish.

The second of the three shirts described as being prepared in the mannerof the foregoing example, and an essentially identical shirt that isfinished with the use of corn starch, after being ironed, are hung sideby side in a clothes closet on hangers. They are permitted to remain inthis condition for 6 months, and thereafter inspected. The shirtfinished with corn starch has turned distinctly yellow. The shirtfinished with the composition of Example 1 remains white.

The third shirt described as being prepared according to the presentinvention is immediately placed into service and worn, being worndeliberately until conspicuously dirty on the cuffs and inside thecollar. A mans white cotton shirt of essentially identical fabricfinished without the product of the present invention is similarly wornto approximately the same degree of soil.

Both soiled shirts are simultaneously laundered in the same batch in anautomatic washing machine, centrifuged together to reduce moisturecontent, and dried together in an artificially heated tumble dryer. Theshirts are then inspected. The shirt ironed with the air of the methylcellulose dispersion of the present invention before soiling is for allpractical purposes completely clean. Visible stains remain inside thecuff and inside the collar of the shirt of which the finishing omits thepresent aqueous dispersion. The function of the starch substitute of thepresent invention as a soil release agent is thus established.

Example 4: In the present example, the cellulose ether was predominatelymethoxy substituted, to the extent of 28 to 30 percent of the availablesubstitutable sites, but contained in addition between 7 and 12 percenthydroxypropoxy substituents. A 2 percent aqueous solution of theresulting ether manifested a thermal gelation tem- 5 perature ofapproximately 60 C., and had an Ubbelohde viscosity of 5 centipoises.Two grams of the cellulose ether were dispersed in 25 milliliters hotwater, and diluted to 100 milliliters by the addition of cold Water toobtain a room-temperature aqueous dispersion of the said celluloseether. The resulting aqueous dispersion was modified by the additionthereto of 0.3 gram of a commercial lubricant emulsion of a highmolecular weight polydimethylsiloxane, 0.2 gram of a commercialfoam-breaking colloid consisting essentially of a polyvalent metallicsoap, non-ionic emulsifier, and hydrocarbon carrier; and the resultingdispersion was further modified by the addition to it of 3 grams of2-butoxyethanol.

The resulting essentially clear aqueous dispersion was positioned in a 6ounce aerosol can, sealed, and pressurized by the injection of 11.5grams of isobutane propellant.

Example 5: 7 grams Methocel MC400 methyl cellulose were disposed in 100grams hot water at between and C., whereupon the Methocel became wettedand formed a viscous solution. To this was then added 279 grams coldwater. To the resulting solution was then added 12 grams2-butoxyethanol, 0.8 gram of a commercial foam-breaking colloidconsisting essentially of a polyvalent metallic soap, a nonionicemulsifier and a hydrocarbon carrier; and 1.2 grams of a commercialemulsion of a polydimethylsiloxane oil of a molecular weight on theorder of 5 X10 As a result of these procedures there was obtained amilky, viscous, opaque fluid product, a total of, to a roughapproximation, 400 grams.

The product was then disposed in a gas-propelled spray can, whichcarried an eduction tube and valve mechanism; on a vacuum line underabout 15 pounds pressure per square inch absolute a substantial part ofcontents of air was removed from the capped can, and thereafter the canwas charged with isobutane in sufiicient amount to produce a pressure ofabout 50 pounds per square inch gauge within the can.

The pressure canned product containing the preparation made withMethocel MC400 was compared with a preparation otherwise essentiallyidentical but based upon a methyl cellulose of which a 2 weight percentaqueous solution at 20 C. has an Ubbelohde Viscosity of 10 centipoises,known commercially as Methocel MClO, said product being exactly aproduct of Example 1.

In particular, products from each of the cans were sprayed on to acotton laboratory towel, in a manner representative of household use ofa spray starch.

The product based upon Methocel MClO issued from the spray actuator as afine mist in a broad, uniform cone, was readily and uniformly disposedover the cloth, and quickly penetrated it, leaving the fabric appearinguniformly moist.

The product based upon Methocel MC40O issued from the spray actuator asheavy, almost particulate, irregular masses: manifested little tendencyto break as a cone, and reaching the fabric as heavy, viscous, whitedeposits, not suitably covering the entire fabric. When enough wasapplied to cover the whole surface of the fabric, the resulting foamexpanded to a total depth of about one half to three quarter inch,completely hiding the fabric. The expansion was imputed to thevaporization of emulsified or otherwise entrapped isobutane. The foamdeposits remained intact for an extended period of time, longer than theobservation period.

The product based upon Methocel MC400 was judged to be unsuited to beused as a fabric treatment applied in the manner herein described; oneusing it would have to apply a hot iron to a conspicuous deposit ofrelatively stable foam. No practice of domestic treatment of fabrics,and in particular no practice of starching, sizing,

- or the like is believed to accept such practice.

Example 62 Tests were carried out on fabric with no treatment, fabricsprayed according to package directions with Magic Finish a commercialspray starch substitute product of Armour & Co., Inc. and fabric sprayedwith a preferred embodiment of this invention.

A sample of the said Magic Finish as commercially sold, was analyzed andfound to contain 1.90 percent of the sodium salt ofcarboxymethylcellulose, 0.10 percent of a silicone containing recurringhydroxy-alkoxy moieties along a siloxane structure (a glycol silicone)and 0.03 percent of a polyethylene glycol of average molecular weightapproximately 200. In this formula, the sole sizing component was thesodium salt of carboxymethylcellulose.

Fabric was sprayed with Magic Finish according to package directions.

Another fabric sample was similarly treated with a product of thepresent invention of which the composition, exclusive of water andpropellant, as weight percent of non-propellant spray can contents was1.75 percent methyl cellulose of which the 2 weight percent aqueoussolution has a viscosity of centipoises (Methocel MC10), 0.30 percent ofpolydimethylsiloxane emulsion (Dow Corning EF-1-1034 emulsion), 0.20percent of a foam breaking colloid consisting essentially of apolyvalent metallic soap, a nonionic emulsifier and a hydrocarboncarrier; and 3 percent of the monobutyl ether of ethylene glycol, apreferred embodiment of this invention in which the sole sizingcomponent was the said methyl ether of cellulose.

All samples were treated alike except for starch substitute materialemployed, and all results were read in identical procedures and with thesame apparatus, and all tests were replicated and replicate results wereaveraged, and the difference in results indicate solely the differencein starch substitute material employed.

Scorch results were read by comparing a refiectometer reading from agroup of unscorched areas with a group of readings from different partsof an area heated by the presence of a thermostat controlled electriciron set at the temperature needed to iron linen and having a surfacetemperature varying between 250 and 215 C., under its own weight and inposition for 60 seconds. In such tests, a higher reflectometer readingindicates less scorching and is therefore more desirable.

When unscorched area readings are converted to the arbitrary value of100%, and scorched areas converted proportionally, scorched areareadings and products with which they were treated were as follows:

Percent Control, no treatment 94 Sodium salt of carboxymethylcellulose(Magic Finish) 69 Methyl ether of cellulose (formula hereinabove) 95.5

The label of the commercial product of which the sole sizing componentwas the sodium salt of carboxymethylcellulose clearly warned users thatthe thermostat control of an electric iron was to be set one fabricposition lower in temperature than was called for on the conventionalposition plate on the iron. Failure to do so resulted in ready scorchingof fabric treated with the sodium carboxymethylcellulose.

Example 7: The phenomenon of scorching of fabric treated with variouscarbohydrate derivative substances was studied. In particular, watersolutions were prepared each containing 1.5 percent of water solublecarbohydrate derivative by weight of total solution, the carbohydratederivative in one solution being a commercial sodium carboxymethylcellulose and in the other solution being a methyl ether of cellulose ofwhich the standard 2 weight percent water solution at C. had anUbbelohde viscosity of ten centipoises: the solutions contained nothingelse. They were applied to areas of white cotton fabric and theso-treated areas permitted to evaporate to dryness. The treated areaswere then tested for scorching in substantially the manner described inExample 6 except that, upon different treated areas variou timeintervals of contact with hot iron Were employed. It was ascertainedthat areas treated with sodium carboxymcthyl cellulose scorched muchmore readily than did means treated with methyl cellulose.

After replication of the test with various water soluble carbohydratederivative polymers it became routine to identify the area treated withsodium carboxymcthyl cellulose by the ease with which it developedscorch. It was ascertained also that the tendency to scorch under theheat of the iron was inherently a property of the alkali metalcarboxyalkyl cellulose; it was not made significant- 1y better orsignificantly worse by employment of any additives that were routinelytested in conjunction with the preparation of practical products of thisinvention. In contrast, methyl cellulose showed less tendency to scorchthan did the fabric upon which it was deposited. Its freedom from scorchwas not significantly changed by any substances employed as additives.

The resulting composition was tested in the ironing of white cottonfabric and found to be highly satisfactory, essentiallyindistinguishable from that of Example 1.

In practicing this invention, no substitute for, and no full equivalentof the methylcellulose as defined, is known. This methylcellulose usedaccording to the present invention has, in comparison with alternativesubstances, these advantages: thermal gelation when wet, and resultinggood behavior under the iron; good hand in the resulting ironed productwith freedom from sharp break creasing and ease of eradicating undesiredcreases accidentally ironed in; excellent usefulness in touch up"ironing of part of a garment; high resistance to highlight scorching;high stability against yellowing with age in air; inhospitality todegradative microorganisms without need for a preservative; andessentially, freedom from corrosion in metal containers for lack ofactive metal or hydrogen ions.

As lubricant, none is critical but available substances havingproperties that are satisfactory in the present invention and lose noneof the advantages of this inven tion include any essentially colorlessilicone oil emulsion. A mineral oil can be used but may not bepreferred because, at rates giving good lubricity such an oil tends toleave oleophanous areas that appear discolored. Polyglycols can be usedas lubricants but care should be exercised in selecting one to avoid anywith low scorch temperatures.

As emulsion breaking agents, any of various commercial foamicides can beused, such as Colloid 5SlB., which comprises a polyvalent metal salt ofhigher fatty acids, with a hydrocarbon oil; tri-n-butyl phosphate can beused; various oily aliphatic substances are known as emulsionbreakingagents. Various such agents appear in US. Patents 1,957,513, 2,425,828,and 2,302,187.

Propellants hardly require discussion. Isobutane, the Freons,fluorocarbons, mixtures of Freons and fluorocarbons and the like can beused. Can pressures of about 40 p.s.i.g. at 20 C. have beensatisfactory.

Adding an agent to enhance the temporary dispersibility of propellant inthe essentially aqueous preparation may gave a better spray pattern. Amonoalkyl ether of a glycol is such an agent, for example2-butoxyethanol.

I claim:

1. In combination as a composition in a spray container and underpressure of an at least partially and temporarily emulsifiablepropellant that, at room temperatures, is typically a rapidlyvaporizable liquid, an aqueous dispersion comprising from 0.1 to 5percent by weight of total aqueous dispersion of a methyl ether ofcellulose that is characterized by these properties:

its standard 2 weight percent aqueous dispersion has an Ubbelohdeviscosity of from 5 to 25 centipoises and the thermal gelationtemperature of its aqueous dispersion is not above C.; and

a foam breaking agent, the balance of said composi- 4. Composition ofclaim 3 containing also a lubricant.

tion being essentially water. 2. Composition of claim 1 containing alsoa lubricant. 0 references tilted. 3. Composition of claim 1 containingalso an agent I to enhance the at least temporary emulslfication of the5 MORRIS LIEBMAN Pnmm'y Emmmer' propellant. H. H. FLETCHER, AssistantExaminer.

U.S. DEPARTMENT OF COMMERCE PATENT OFFICE Washington, D.C. 20231 UNITEDSTATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,402,056September 17, 1968 John W. Ehrmantraut It is certified that errorappears in the above identified patent and that said Letters Patent arehereby corrected as shovm below:

In the heading to the printed specification, line 3, "John W.Ehrmantraus" should read John W. Ehrmantraut Signed and sealed this 10thday of March 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer

